1. Field of the Invention
The present invention relates to polypeptides having larvae growth inhibiting or insecticidal effect on Scarabaeidae insects, to polynucleotides encoding the same, to controlling agents for controlling Scarabaeidae insects containing the polypeptides as active ingredients, and to a method of controlling Scarabaeidae insects using the polypeptides.
2. Description of the Related Art
Larvae of Scarabaeidae insects eat roots of a wide variety of plants such as turf, agricultural crops, horticultural crops and trees and bushes and cause serious damage thereto. A large number of reports have been made on damages caused by, especially, Anomala cuprea, Blitopertha orientalis, and Popillia japonica to a lawn of golf courses, a sweet potato field, and a peanut field. In particular, Anomala cuprea, which is particularly large in size, does considerable harm thereto due to its eager appetite.
However, conventional ground spreading of chemical pesticides is difficult to give a controlling effect since these larvae inhabit in the ground and are difficult to locate them, and thus it was necessary to spread a large amount of chemical pesticides over a wide range of the surface of the ground and penetrate them into the ground. Therefore, there were concerns about adverse influences of the chemical pesticides on the natural environment and human bodies, and there has been a keen desire for a biological controlling method that can replace the chemical pesticides.
As one of the biological controlling methods for controlling Scarabaeidae insects, attempts to utilize bacteria belonging to Bacillus popilliae have been tried over a long period of time. The bacteria are parasitic to larvae of Scarabaeidae insects as hosts and infect to them per os usually in a form of sporangia, propagate in large amounts in hemolymph to cause milky disease and finally lead the larvae to death.
Recently, an amino acid sequence of a polypeptide constituting a parasporal body of a strain belonging to Bacillus popilliae, i.e., Bacillus popilliae subsp. melolonthae H1, and a nucleotide sequence of the gene encoding the polypeptide were partly clarified (J. Bacteriol. Vol. 179, p.4336–4341 (1997)), and it has been reported that the polypeptide constituting the parasporal body of Bacillus popilliae subsp. melolonthae H1 has a controlling effect on Melolontha melolontha (WO97/14798). However, it was not clarified whether the bacterial strain and a polypeptide thereof have controlling effects on Anomala cuprea, Blitopertha orientalis and Popillia japonica, each of which belongs to different species.